In recent years, a wireless local area network (LAN) typified by Institute of Electrical and Electronics Engineers (IEEE) 802.11 has been spread, and, in accordance with the spread, an information amount of content to be transmitted and products supporting the wireless LAN have increased. Therefore, in order to improve communication efficiency of an entire network, standards of IEEE 802.11 are currently still expanded.
As an example of expansion of the standards, in 802.11ac standards, multi-user multi-input multi-output (MU-MIMO) for downlink (DL) is employed. MU-MIMO is a technology which enables a plurality of signals to be transmitted in the same time slot by space division multiplexing, and, with this technology, it is possible to, for example, improve utilization efficiency of frequencies.
However, there is a case where transmission periods of frames transmitted by a plurality of communication apparatuses are different, in which case, the number of times of multiplexing of frames received during a reception period of the frames increases or decreases. Therefore, reception power at a communication apparatus which receives the multiplexed frame changes during the reception period, and change of the reception power can affect reception performance. To address this, a method for making transmission periods of frames the same is proposed.
For example, Patent Literature 1 discloses a communication apparatus which makes transmission periods of a plurality of frames the same by adding padding to the plurality of frames having different transmission periods as appropriate.